Oh, and Rufus is fast. For instance it's about twice as fast as UNetbootin, Universal USB Installer or Windows 7 USB download tool, on the creation of a Windows 7 USB installation drive from an ISO. It is also marginally faster on the creation of Linux bootable USB from ISOs. (1)
A non exhaustive list of Rufus supported ISOs is also provided at the bottom of this page. (2)

System Requirements:

Windows XP or later, 32 or 64 bit doesn't matter. Once downloaded, the application is ready to use.

I will take this opportunity to express my gratitude to the translators who made it possible for Rufus, as well as this webpage, to be translated in various languages. If you find that you can use Rufus in your own language, you should really thank them!

Usage

Download the executable and run it – no installation is necessary.

The executable is digitally signed and the signature should state:

"Akeo Consulting" (v1.3.0 or later)

"Pete Batard - Open Source Developer" (v1.2.0 or earlier)

Notes on DOS support:

If you create a DOS bootable drive and use a non-US keyboard, Rufus will attempt to select a keyboard layout according to the locale of your system. In that case, FreeDOS, which is the default selection, is recommended over MS-DOS, as it supports more keyboard layouts.

Notes on ISO Support:

All versions of Rufus since v1.1.0 allow the creation of a bootable USB from an ISO image (.iso).

Creating an ISO image from a physical disc or from a set of files is very easy to do however, through the use of a CD burning application, such as the freely available CDBurnerXP or ImgBurn.

Notes on UEFI & GPT support:

Since version 1.3.2, Rufus support UEFI as well as GPT for installation media, meaning that it will allow you to install Windows 7, Windows 8 or Linux in full EFI mode.
However, Windows Vista or later is required for full UEFI/GPT support. Because of OS limitations, Windows XP restricts the creation of UEFI bootable drives to MBR mode.

Source Code

If you are a developer, you are very much encouraged to tinker with Rufus and submit patches.

Donations

Since I'm getting asked about this on regular basis, there is no donation button on this page.

The main reason is that I feel that the donation system doesn't actually help software development and worse, can be guilt-inducing for users who choose not to donate.

Instead, I think that "mécénat"; or developer patronage, from companies which benefit most from a healthy FLOSS ecosystem, is what we should be aiming for. This is because, unless they are backed by a company, developers who want to provide quality Open Source software cannot realistically sustain full time development, no matter how generous their software users are.

Also, unless you are blocking them (hint, hint), you'll notice that there are ads on this page, which I consider sufficient revenue enough.

Finally the fact that I have the freedom to develop Free Software in my spare time should indicate that I'm well-off enough, and therefore that you should direct your generosity towards people who need it a lot more than I do. If you really insist, you can always make a donation to the Free Software Foundation, as they are the main reason software like Rufus is possible.

At any rate, I'll take this opportunity to say thank you for your continuing support and enthusiasm about this little program: it is much appreciated!

But please continue to feel free to use Rufus without any guilt about not contributing for it financially – you should never have to!